1. Field of the Invention
The present invention relates to annular seals for self-cleaning sludge centrifuges.
2. Description of the Prior Art
Annular seals for self-cleaning sludge centrifuges are well known, such as shown in Danish Patent No. 127041. The annular seal disclosed in this patent has its soft ring part joined to the reinforcement part in such a way that the soft material covers the reinforcement part's top in such a manner that the soft material seals directly against the upper bowl part when the slit is closed. This arrangement has shown itself to be accompanied by serious drawbacks as the soft material is squeezed between the two hard parts, has a tendency to flow outwardly under the influence of the centrifugal force, and is quickly eroded in its exposed position by the outflowing solid particles. Furthermore, in such an arrangement it is difficult to perform so called "partial shots" because the soft material is not able to "bite" the sludge flows over. These disadvantages of the prior art are overcome by the present invention.